Comeback Without Sounding Beta?

Used to flirt with this chick on Facebook couple of months ago. She was into me, but I couldn't really escalate as I had to deal with my ex back then. And it faded away slowly.

To cut short, I inboxed her on Facebook two weeks ago. An interesting opener, one neg, maintained the playful frame, and I got her to give me her number in just three messages. Again, I could see how much she was into me. Texted her on WhatsApp after a couple of days -

"X Coffee Shop. Friday. 15.00"

She hasn't replied, though. It could be either 'cause of me coming off as too cocky, or she probably doesn't know it was me(I never gave her my number before I texted her). I would have called her up, but I just realized she's currently at a different city. What do I text her to come out of this without sounding lame? Probably tease her for her lack of reply? Suggestions are much appreciated.